problem with PHP4

[c00lk1d]

I am working on a class but i ran into some problems.

will display:

After Sub Creation
After Sub Creation

for PHP5(this is how i want it)

but in php for it will display:

After Sub Creation
Before Sub Creation

thats not what i want, any idea on how to fix it?

<?php
class MyClass{
	var $name;
	var $sub;

function MyClass(){
	$this->name = 'Before Sub Creation';
	$this->sub = new sub($this);
	$this->name = 'After Sub Creation';
}
function show(){
	echo $this->name.' (Parent)';
}
}
class sub{
	var $parent;
	function sub($obj){
		$this->parent = $obj;
	}
	function show(){
		echo $this->parent->name.' (Sub)';
	}	
}

$Test = new MyClass();
$Test->Show();
echo '<br>';
$Test->sub->Show();
?>

[Shrike]

Hmm I think that is called a circular reference - not sure though. You are storing the instance of sub in the instance of MyClass and yet passing the instance of MyClass to sub. Wacky 🙂

As for the problem - I see that you are using PHP 5. PHP 5 passes objects by reference by default - so any changes you make on the original will be reflected in the reference (passed to the sub instance).

[c00lk1d]

Originally posted by Shrike
Hmm I think that is called a circular reference - not sure though. You are storing the instance of sub in the instance of MyClass and yet passing the instance of MyClass to sub. Wacky 🙂

As for the problem - I see that you are using PHP 5. PHP 5 passes objects by reference by default - so any changes you make on the original will be reflected in the reference (passed to the sub instance).

Yes but is there any way to make PHP4 do that too?

edit://
let me try to explain why i want it.
i'm working on a class to resize image.
$image->gd->resize(..);

is how i want to call the functions
but here is a
$image->setup(); function with this the user can set if he want interlaced, and other options

so would like to be able to get those settigns form inside the gd class, becouse theu can change. small example:

$img = new image;
$img->setup('/bin/convert', true, 100);
$MyImage = $img->gd->load('myfile.jpg');
$MyImage = $img->gd->resize($MyImage, 50%);
$img->gd->save($MyImage, 'MyImage_hightQ.jpg');
$img->setup('/bin/convert', false, 50);
$img->gd->save($MyImage, 'MyImage_LowQ.jpg');

i got this working fine under php5, but my prodoction server is a php4 :/

[Shrike]

In PHP 4 you create references using the ampersand character.

$this->sub =& new sub($this); 
// and in class sub()
$this->parent =& $obj; 

I have no idea if this will cause problems due to the circular reference though.

[c00lk1d]

i've added the & before the new when the object is create and before where i set the parent. no effect.

[Shrike]

You only really need the ampersand before the 'new' statement if you want to create a circular reference. I also missed out something in my first post, so here goes:

class sub{
    var $parent;
    function sub(&$obj){
        $this->parent =& $obj;
    }
    function show(){
        echo $this->parent->name.' (Sub)';
    }    

} 

http://shrike.webchimps.com/test.php

[c00lk1d]

ok, i give it another whirl... i'll let you know if it works wich it seems to do 🙂

edit: works like a charm thanx a lot

[c00lk1d]

<?php
class MyClass{
    var $name;
    var $sub;

function MyClass(){
    $this->sub = new sub($this);
}
function setup($newname){
    $this->name = $newname;
}
}
class sub{
    var $parent;
    function sub(&$obj){
        $this->parent =& $obj;
    }
    function show(){
        echo $this->parent->name;
    }    

}
$Test = new MyClass();
$Test->setup('jorge-');
$Test->sub->Show();
$Test->setup('leo-');
$Test->sub->Show();
$Test->setup('martine');
$Test->sub->Show();
?> 

doest work though 🙁:glare:

[mrhappiness]

class MyClass{
    var $name;
    var $sub;

function MyClass(){
    $this->sub = &new sub($this);
}
function setup($newname){
    $this->name = $newname;
}
}
class sub{
    var $parent;
    function sub(&$obj){
        $this->parent =& $obj;
    }
    function show(){
        echo $this->parent->name;
    }    

}
$Test = &new MyClass();
$Test->setup('jorge-');
$Test->sub->Show();
$Test->setup('leo-');
$Test->sub->Show();
$Test->setup('martine');
$Test->sub->Show();

[c00lk1d]

thanx, now it works 🙂